Nasotracheal or orotracheal intubation is commonly used to secure a patient's airway to maintain an open airway, and is frequently used to provide ventilation to the lungs or minimize the possibility of airway obstruction in a patient. In orotracheal intubation, an endotracheal (“ET”) tube is inserted through a patient's mouth and into the patient's trachea. In nasotracheal intubation, a nasotracheal tube is inserted through a patient's nostril and into the patient's trachea.
When a patient is intubated, proper placement of the ET tube in the trachea may be important to minimize the possibility of negative complications associated with intubation. For example, if the distal end of the ET tube is not sufficiently advanced into the trachea, there may be an increased risk of accidental extubation when the ET tube is dislodged from the trachea and can no longer maintain an open airway or provide ventilation. Conversely, advancement of the distal end of the ET tube too far into the trachea may cause the ET tube to enter the bronchial passageways. Such bronchial intubation may lead to hypoxia, pneumothorax, or even death. Accordingly, current clinical practice recommends positioning the distal tip of an ET tube between 2 cm and 5 cm proximal to the carina, an anatomical structure located at the bifurcation of the trachea.
Currently, the primary manner of determining positioning of an ET tube is a post-intubation chest x-ray (“CXR”). CXR is generally expensive and exposes the patient to radiation, and is thus not a practical solution for repeated checks. Current alternatives to CXR suffer from several shortcomings. For example, clinical observations such as symmetrical chest expansion and auscultation regularly result in inaccurate tube placement (e.g., incorrect placement in as many as 20% of intubations using clinical observations). Sonography, ultrasound, and bronchoscopy require expensive capital equipment and specialized training, which makes these techniques impractical for frequent usage at many sites of care. Lighted stylets (such as TrachLight™) that use transillumination only provide positioning with respect to external landmarks, which do not necessarily correlate to the location of the carina. Additionally, these lighted stylets may not function properly in certain obese patients, and require a light source which adds expense and a power requirement.